(1) Technical Field
This disclosure relates generally to the field of white LED drivers and relates more specifically to white LED drivers with improved efficiency.
(2) Background
White light emitting diodes (WLED) are used most often in notebooks and desktop screens, and in virtually all mobile LCD screens. A WLED is typically a blue LED with broad-spectrum yellow phosphor to give the impression of white light. WLEDs are often used for backlighting LCD displays. For such an application WLED drivers have to generate constant current required for a constant luminance.
Charge pumps or inductive converters are usually used as WLED drivers, generating high bias voltages from a single low-voltage supply, such as a battery.
It is a challenge for engineers designing WLED drivers to optimize efficiency of the drivers.